Crane counterweight support and means for removing and mounting same

ABSTRACT

A Crane has a shiftable counterweight thereon. The counterweight is shifted by a fluid ram which can also be used to remove or mount the counterweight relative to the crane.

United States Patent [191 Lamer et a1.

[ Dec. 9, 1975 CRANE COUNTERWEIGHT SUPPORT AND MEANS FOR REMOVING AND MOUNTING SAME [75] Inventors: Gerald P. Lamer, Rothschild;

Ronald L. Zyduck, Mosinee, both of Wis; David F. Roesler, Edina, Minn.

[73] Assignee: J. I. Case Company, Racine, Wis.

[22] Filed: Apr. 22, 1974 [21] Appl. No.: 462,978

[52] US. Cl. 212/48; 214/127; 214/142; 280/150 E 51 Int. cl. B66C 23/72 [58] Field of Search 212/47, 48, 49; 214/127, 214/142; 280/150 E [56] References Cited UNITED STATES PATENTS 3,240,353 3/1966 Leavesley 212/48 3,375,021 3/1968 Grider 212/49 3,501,021 3/1970 Schreier .7 214/142 X 3,595,410 7/1971 Lemmon 280/150 E 3,777,900 12/1973 Brewer 212/48 FOREIGN PATENTS OR APPLICATIONS 964,154 7/1964 United Kingdom 212/49 668,920 10/1964 Italy 212/49 1,103,173 2/1968 United Kingdom 212/49 106,656 4/1965 Norway 212/49 216,381 9/1957 Australia 214/142 1,267,396 5/1968 Germany 212/49 Primary ExaminerRobert J. Spar Assistant Examiner-R. B. Johnson Attorney, Agent, or Firm-Dressler, Goldsmith, C1ement & Gordon, Ltd.

57 ABSTRACT A Crane has a shiftable counterweight thereon. The counterweight is shifted by a fluid ram which can also be used to remove or mount the counterweight relative to the crane.

8 Claims, 4 Drawing Figures U.S. Patent Dec. 9, 1975 Sheet 1 of 2 3,924,753

3 Hulk. J IN wk w K N x @w R l W lli Sheet 2 of 2 v US. Patent Dec. 9, 1975 cRANE COUNTERWEIGHT SUPPORT AND. I MEANs FOR REMOVING AND MOUNTING SAME BACKGROUND OF THE INVENTION Shiftable counterweights for cranes or other types of heavy duty machinery have been known for years.

In recent years the increased capacity and size of the crane has resulted in a corresponding increase in the mass of the counterweight. In fact, the size of the crane and the counterweight have resulted in some problems in transporting the equipment. Because of weight limitations that are placed on most roads, it has become necessary to remove the counterweight from the crane and transport the counterweight separate from the crane when the unit is being moved along most roadways.

One type of system that has been proposed is disclosed in US Pat. No. 3,726,416. While this type of system serves the purpose of having a shiftable counterweight as well as being able to remove the counterweight from the crane, the system disclosed in this patent requires separate equipment for removing the counterweight. Furthermore, before removing the counterweight, it is necessary to physically attach the counterweight to a crane boom section before it can be manipulated. This arrangement is not only time consuming but also requires ancillary equipment.

SUMMARY OF THE INVENTION According to the present invention, a counterweight is supported on a crane and is extended and retracted by a fluid ram which may also be utilizedto raise and lower the counterweight for removal. The counterweight can be lowered to the ground or other vehicle by simply removing a single pin.

More specifically, the-counterweight is supported on an extensible and retractable carriage which is pivoted on the base for the crane and the extensible and retractable elements of the carriage are moved relativeto each other by a fluid ram. The carriage is normally supported in a fixed position by support means which can be manipulated to accommodate pivotal movement of the counterweight carriage on the base by the fluid ram. In the specific embodiment illustrated, the support means consists of a beam or member that extends from the base and has releasable latch means on the outer end thereof which cooperates with the pivotally supported element of the carriage to hold the carriage in a fixed position. When it is desired to remove the counterweight from the crane, the releasable latch means or pin is removed to allow pivotal movement of the counterweight and carriage with respect to the base for the crane.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS FIG. 1 is a side elevational view of a crane having the present invention incorporated therein;

FIG. 2 is an enlarged fragmentary view of the counterweight system; I

FIG. 3 is a further enlarged view similar to FIG. 2;

and A FIG. 4 is a section through the support carriage, as viewed along line 44 of FIG. 3.

DETAILED DESCRIPTION While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail a preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated.

FIG. 1 shows a large mobile crane 10 having the present invention incorporated therein. Mobile crane 10 consists of a vehicle or support 12 having a turntable or base 14 rotatably supported thereon for rotation about a vertical axis. An extensible and retractable crane boom 16 is pivotally supported on base 14 for vertical movement by horizontal pivot means 18.

FIGS. 2 and 3 show the details of the counterweight system including the counterweight and its support. The counterweight system for crane 10 includes a counterweight support structure consisting of a carriage 20 having first and second extensible and retractable elements 22 and 24. First element 22 is pivotally supported by pivot means or a pin 26 on base 14 so that the entire counterweight carriage may be pivoted in a vertical plane, for a purpose that will be described later. Second element 24 has releasable counterweight connecting means on the outer end thereof for supporting a counterweight 30.

Inthe illustrated embodiment, the releasable counterweight connecting means consists of a pair of hooks 32*(only one being shown): which are pivotally supported on element 24 by pins 34. counterweight 30 has a permanent cross pin 36 thereon which is received intothe end of hooks 32 so that the counterweight is pivotally supported on carriage element 24.

i To prevent pivotal movement of the counterweight on carriage 20 during normal extension and retraction, releasable counterweight connecting means also include a lug 38 secured to counterweight 30 and a bracket 40 extending from carriage element 24. Lug 38 and bracket 40 have openings which are aligned when the counterweight system is in the position illustrated in FIG. 2 so that a removable pin 42 may be inserted through the openings to prevent swinging of the counterweight about the support pins 34.

The counterweight support structure also includes support means-:on the base that cooperate with the counterweight carriage for normally supporting the carriage in a substantially fixed position relative to the base and accommodating pivotal movement of the counterweight Carriage on thebase. The support means consists of an elongated arm or member 44 that has one end fixed to base 14 and extends generally horizontally away from base 14. The outer end of member or arm 40 incorporates releasable latch means 46 for normally holding carriage 20 in a substantially fixed position relative to base 14. In the illustrated embodiment, releasable latch means 46 consists of a pair of legs 48 depending from member 44 and positioned to extend on opposite sides of carriage eleriifit 22 with the lower edges of legs 48 extending below the lewer edge of carriage element 22. The two legs 48 have horizontally aligned openings at the lower end tltff that a pin 50 may be inserted through the opefilfig= Plfi or releasable pin means 50 and legs 48 cooperate tQ define a cradle which supports counterweight Efllfi e 28 lfi 'a substantially fliid position, as shown in Fl 2:

Carriage elements 22 and 24 are extended and retracted relative to each other by extensible fluid ram means 52 consisting of a cylinder or first element 54 pivotally supported on base 14 by a pin 56. Fluid ram means 52 also includes a piston rod or second ram element 58 that has its outer end connected by a pin 60 to carriage element 24. Thus, extension and retraction of ram elements 54 and 58 will produce telescoping movement between carriage elements 22 and 24 so that the position of counterweight 30 can be changed rela tive to base 14, which will change the position of the center of gravity for the counterweight system with respect to base or turntable 14. To prevent carriage element'24 from being separated from carriage element 22, the two carriage elements also have cooperating means defining the fully extended position for carriage elements 22 and 24. Referring to FIG. 4, it will be noted that carriage elements 22 and 24 are rectangular or hollow polygonal members that are telescoped relative to each other. The inner end of the second or outer telescoping element 24 has a roller 70 positioned to engage the-upper, inner surface of the first element 22. The inner end of carriage element 24 also has wear plates 72 which engage the inner surfaces of element 22. The outer end of the first or inner telescoping carriage element 22 has pins 74 extending through opposite sides thereof with the inner ends of pins 74 located in the path of movement of wear plates 72. Thus, pins 74 and wear plates 72 cooperate to define stop means which defines the fully extended position for carriage elements 22 and 24.

While one type of stop means has been specifically described, it will be appreciated that the fully extended position could readily be defined by other means, such as an additional set of wear plates located on the inner surface adjacent the outer end of carriage element 22 to be located in the path of movement of wear plates 72. Another type of stop means could be a bar that is welded to the outside of telescoping element 24 which would engage a plate welded to the outer end of telescoping element 22.

.During normal use, telescoping elements 22 and 24 are extended and retracted relative to each other by ex tension and retraction of ram elements 54 and 58. However, according to an important feature of the present invention, the fully extended position, defined by stop means 72 and 74, is reached before fluid ram 52 is in a fully extended position. Thus, when it is desired to remove the counterweight from the crane, it is only necessary to continue extension of fluid ram 52 after elements 22 and 24 are in the fully extended position. Thiswill then pivot carriage and counterweight about horizontal pivot pin 26 to a point where car:

riage 20 engages a lower edge of member 44. When this position is reached, the weight is removed from pin 50 so that the pin can be removed with a minimum force. After the pin has been removed, retraction of fluid ram 52 will cause carriage 20 to pivot about horizontal pivot pin 26 and allow the counterweight to be lowered to the ground. Before lowering the counterweight to the ground, removable pins 42 are also removed so that the counterweight will pivot about a horizontal pivot 4 can also be utilized for raising and lowering the counterweight with respect to the supporting base. It will be appreciated that while a single carriage element has been shown and described in the preferred embodiment of the present invention, two telescoping car riages 20 are envisioned and these carriages would be horizontally spaced from each other with the outer ends of the second elements 24 interconnected by a said counterweight; extensible fluid ram means having axis defined by pins 34. The lowered position for the the present invention'provides a simple and inexpensive method and apparatus for shifting a counterweight relative to a boom and in which the shifting mechanism one end connected to said base and an opposite end connected to said other element for extending and retracting said elements; and support means on said base cooperating with said counterweight carriage,-said support means including a member fixed to said base and extending along said one element above said horizontal pivot means and releasable latch means carried by said member and including a pair of vertically depending legs being located on opposite sides of said one element at a location spaced from said horizontal pivot means with free ends located below a lower edge of said one element, said releasable latch means'also including releasable pin means extending between said legs below said lower edge, said releasable latch means defining a cradle supporting said counterweight carraige so that said support means (I) normally supports said carriage in a substantially fixed position relative to said base and (2)-accommodates pivotal movement of said counterweight carriage on said base so that said counterweight may belowered and removed from said base.

2-. A crane as defined in claim 1, in which said ram means includes first and second extensible and retractable ram elements movable between fully retracted and fully extended positions, said ram elements, when moved to the fully extended position, pivoting said counterweight carriage away from said releasable pin means to allow for removal of said releasable pin means to accommodate pivotal movement of said counterweight carriage away from said member and lower said counterweight.

3. A crane as defined in claim 2, in which said carriage elements are polygonal and are telescoped relative to each other.

4. A crane as defined in claim 3, in which said releasable counterweight connecting means normally holds said counterweight fixed with respect to said other carriage element and incorporates releasable means to accommodate relative pivotal movement between said other element and said counterweight.

5. In a crane having a base with an extensible and retractable boom supported on said base; a counterweight; a counterweight carriage having first and sec ond elongated relatively extensible and retractable elements; horizontal pivot means supporting one of said elements for pivotal movement on said base; means on said other element for supporting said counterweight; extensible fluid ram means having one end connected to said base and an opposite end connected to said other element for extending and retracting said ele ments; a substantially horizontal elongated support arm on said base extending generally parallel to and above said one of said elements; and releasable latch means carried by said arm and cooperating with said counterweight carriage for normally supporting said carriage in a substantially fixed position on said base for horizontal movement of said elements relative to each other, said latch means being selectively releasable to accommodate pivotal movement of said counterweight carriage on said base so that said counterweight may be lowered by said extensible fluid ram means and removed from said base.

6. A crane as defined in claim 5, in which said elements have cooperating stop means that define a fully extended position for said elements so that extension of said fluid ram means will cause engagement of said stop means and continued extension will pivot said carriage about said horizontal pivot axis to accommodate release of said latch means and subsequent retraction of said fluid ram means will pivot said carraige about said horizontal pivot axis to lower said counterweight.

7. A crane as defined in claim 5, in which said latch means includes a removable pin extending below said one element for normally supporting said carriage in a fixed position.

8. A crane as defined in claim 7, in which said counterweight is pivotally supported on said carriage. 

1. In a crane having a base with an extensible and retractable boom supported on said base; a counterweight; counterweight support structure including a counterweight carriage having first and second relatively extensible and retractable elements; horizontal pivot means supporting one of said elements for pivotal movement on said base; releasable counterweight connecting means on said other element for supporting said counterweight; extensible fluid ram means having one end connected to said base and an opposite end connected to said other element for extending and retracting said elements; and support mEans on said base cooperating with said counterweight carriage, said support means including a member fixed to said base and extending along said one element above said horizontal pivot means and releasable latch means carried by said member and including a pair of vertically depending legs being located on opposite sides of said one element at a location spaced from said horizontal pivot means with free ends located below a lower edge of said one element, said releasable latch means also including releasable pin means extending between said legs below said lower edge, said releasable latch means defining a cradle supporting said counterweight carraige so that said support means (1) normally supports said carriage in a substantially fixed position relative to said base and (2) accommodates pivotal movement of said counterweight carriage on said base so that said counterweight may be lowered and removed from said base.
 2. A crane as defined in claim 1, in which said ram means includes first and second extensible and retractable ram elements movable between fully retracted and fully extended positions, said ram elements, when moved to the fully extended position, pivoting said counterweight carriage away from said releasable pin means to allow for removal of said releasable pin means to accommodate pivotal movement of said counterweight carriage away from said member and lower said counterweight.
 3. A crane as defined in claim 2, in which said carriage elements are polygonal and are telescoped relative to each other.
 4. A crane as defined in claim 3, in which said releasable counterweight connecting means normally holds said counterweight fixed with respect to said other carriage element and incorporates releasable means to accommodate relative pivotal movement between said other element and said counterweight.
 5. In a crane having a base with an extensible and retractable boom supported on said base; a counterweight; a counterweight carriage having first and second elongated relatively extensible and retractable elements; horizontal pivot means supporting one of said elements for pivotal movement on said base; means on said other element for supporting said counterweight; extensible fluid ram means having one end connected to said base and an opposite end connected to said other element for extending and retracting said elements; a substantially horizontal elongated support arm on said base extending generally parallel to and above said one of said elements; and releasable latch means carried by said arm and cooperating with said counterweight carriage for normally supporting said carriage in a substantially fixed position on said base for horizontal movement of said elements relative to each other, said latch means being selectively releasable to accommodate pivotal movement of said counterweight carriage on said base so that said counterweight may be lowered by said extensible fluid ram means and removed from said base.
 6. A crane as defined in claim 5, in which said elements have cooperating stop means that define a fully extended position for said elements so that extension of said fluid ram means will cause engagement of said stop means and continued extension will pivot said carriage about said horizontal pivot axis to accommodate release of said latch means and subsequent retraction of said fluid ram means will pivot said carraige about said horizontal pivot axis to lower said counterweight.
 7. A crane as defined in claim 5, in which said latch means includes a removable pin extending below said one element for normally supporting said carriage in a fixed position.
 8. A crane as defined in claim 7, in which said counterweight is pivotally supported on said carriage. 